A ministry spokesman said in a statement issued after the hearing that the Seven Seas Conqueress, its crew and passengers were detained by the Indonesian authorities in Singapore waters off Pedra Branca.

He added that Singapore has strongly protested against the Indonesian government's actions.

"We have emphasised that there is no basis for Indonesia's detention of the vessel, its crew and passengers, nor for the continued detention of and purported charges brought against Mr Tan," he said.

"In addition, Singapore officials have communicated repeatedly with the relevant Indonesian authorities, at both the national and provincial level, to seek the immediate release of Mr Tan and the vessel, as well as the termination of any purported investigations against him."

MFA said that it immediately sought consular access to Tan once it learnt of his arrest, but that was granted only on Jan 24.